Marc Armstrong, M.D.
NPI 1326453556 · Internal Medicine Physician · Aberdeen, SD
Enrolled with Medicare as Practitioner - Emergency Medicine · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Marc Armstrong, M.D. is a Internal Medicine Physician provider in Aberdeen, SD (NPI 1326453556).
Provider details
- NPI number
- 1326453556
- Entity type
- Individual
- Primary specialty
- Internal Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- No
- License
- TRN16984 (FL)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Student, Health Care
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure28% of score
11 yrs in NPPES registry
- Profile completeness28% of score
100% of core fields populated
- Practice footprint17% of score
2 documented practice locations
- Medicare service volume (vs. specialty peers)28% of score
795 Medicare services, 2024 (ranked within specialty)
Medicare volume is ranked against active providers in the same specialty. Signals a provider has no public data for (e.g. Medicare claims) are left out of the score entirely — never counted as zero — so providers without that data are not penalized. See the full formula and weights in our methodology.
What this provider does (Medicare)
Based on Medicare fee-for-service claims, 2024; not all care is captured.
| Service (HCPCS) | Medicare services | Typical Medicare-allowed (2024) |
|---|---|---|
| Emergency Department Visit With High Level of Medical Decision Making99285 | 486 | $185 |
| Emergency Department Visit With Moderate Level of Medical Decision Making99284 | 186 | $128 |
| Critical Care, First 30-74 Minutes99291 | 123 | $222 |
Typical Medicare-allowed amounts for these services range $128–$222 (2024). The Medicare-allowed amount is what Medicare recognizes for a service under fee-for-service — a reference figure for 2024, not a price quote and not what you would be billed. Medicare Part B covers roughly an eighth of all NPIs (65+ skew); services with fewer than 11 beneficiaries are suppressed by CMS. Source: CMS Medicare Physician & Other Practitioners, by Provider & Service.
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 8 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Oxycodone Hcl/Acetaminophenbrand: Oxycodone-Acetaminophen | 31 | 31 |
| Methylprednisolone | 25 | 25 |
| Ondansetronbrand: Ondansetron Odt | 22 | 22 |
| Prednisone | 21 | 21 |
| Nitrofurantoin Monohyd/M-Crystbrand: Nitrofurantoin Mono-Macro | 17 | 17 |
| Cyclobenzaprine Hcl | 14 | 14 |
| Amoxicillin/Potassium Clavbrand: Amoxicillin-Clavulanate Potass |
Practice location
Mailing address
Additional practice locations (1)
- 11375 Cortez BlvdBrooksville, FL 34613-5409Phone: (352) 597-6137
Registry dates
- Enumerated
- 2014-06-26
- Last updated
- 2018-03-17
Frequently asked questions
- What is Marc Armstrong's NPI number?
- Marc Armstrong's National Provider Identifier (NPI) is 1326453556, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Marc Armstrong's specialty?
- Marc Armstrong is listed in the NPPES registry with a primary specialty of Internal Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is Marc Armstrong located?
- Marc Armstrong's practice location on file with NPPES is 305 S State St, Aberdeen, SD 57401-4527.
- What is Marc Armstrong's phone number?
- The practice phone number listed in the NPPES registry for Marc Armstrong is (605) 622-5100.
- Does Marc Armstrong accept Medicare?
- Marc Armstrong is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Marc Armstrong's NPI active?
- Yes — Marc Armstrong's NPI (1326453556) is active in the NPPES registry as of the last update on 2018-03-17.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.